This invention relates to safety equipment, and in particular to a safety device for a high pressure flow line.
In oil and gas wells, it is often necessary to stimulate the well in order to increase its production. One method is to fracture the producing formation by introducing fluids into the well under extremely high pressure. The high pressure fluids damage the formation by creating cracks or fissures, causing the oil or gas to flow more freely from the formation. This allows more oil and gas to be produced from the well.
The flow lines used for these operations must be able to withstand the high pressures of the fracturing fluids that are introduced into the well. The flow lines are usually only temporarily connected to the wellhead for the duration of the fracturing operation. Even though the flow lines may be designed to withstand high pressures, ruptures in the pipe and coupling failures may still occur. Because of the danger associated with pumping these high pressure fluids, safety precautions must be taken to minimize the hazards created when failures do occur. Breaks in the pipeline used for conducting the pressurized fluids to the wellhead can result in the uncontrolled flailing or whipping of the pipe as the high pressure fluid escapes, particularly if the fluid is gaseous. This creates an extreme hazard to any surrounding persons, equipment or structures.
In the prior art, U.S. Pat. No. 5,689,862 discloses an apparatus and method for anchoring the pipeline which involves positioning pipe clamps near the ends of each pipe section. The clamps are provided with a bore through which a steel cable is threaded. In this way a series of clamps can be anchored with only a single length of cable. The cable is then secured at the ends to a suitable anchoring structure. While the cable is a suitable anchoring method, improvements are desired.
A high pressure flow line that is formed from sections of pipe that are coupled together is provided with a safety restraint assembly. The safety restraint assembly is formed by wrapping short, flexible rib tethers around the pipeline near the ends of each section of pipe. A plurality of long tethers are linked end-to-end to form a continuous spine, which is threaded through all of the rib tethers. Each of the tethers contains continuous filaments. The spine is then anchored at each of its terminal ends to suitable anchoring structures. Alternatively, the safety restraint assembly may utilize anchor assemblies in addition to the tethers.
The foregoing and other objects and advantages of the present invention will be apparent to those skilled in the art, in view of the following detailed description of the preferred embodiment of the present invention, taken in conjunction with the appended claims and the accompanying drawings.